Author: Robert Hyatt
Date: 15:03:52 08/06/02
Go up one level in this thread
On August 06, 2002 at 01:00:04, Robin Smith wrote: >On August 05, 2002 at 17:50:27, Robert Hyatt wrote: > >>On August 05, 2002 at 12:15:32, J. Wesley Cleveland wrote: >> >>>On August 05, 2002 at 03:10:07, Jouni Uski wrote: >>> >>>>[D]8/4rk2/1p2r3/1Pp5/2Pp4/1K1P4/2PQ4/8 w - - >>>> >>>>Crafty's evalution after 14 ply +1,56. >>>> >>>>Jouni >>> >>>Crafty 18.15 static evaluation >>>material evaluation................. 1.60 >>>development......................... 0.00 >>>pawn evaluation..................... -0.04 >>>passed pawn evaluation.............. 0.00 >>>passed pawn race evaluation......... 0.00 >>>king safety evaluation.............. 0.00 >>>interactive piece evaluation........ -0.14 >>>total evaluation.................... 1.42 >>> >>> >>>Crafty 18.10 static evaluation >>>material evaluation................. 0.80 >>>development......................... 0.00 >>>pawn evaluation..................... -0.04 >>>passed pawn evaluation.............. 0.00 >>>passed pawn race evaluation......... 0.00 >>>king safety evaluation.............. 0.00 >>>interactive piece evaluation........ -0.14 >>>total evaluation.................... 0.62 >>> >>>Apparently Bob does believe that Q+P is much better than 2R >> >> >>I believe that in most positions, unless something really unusual is >>happening, that a queen is better than two rooks, when the computer has >>the queen. As a general rule, the queen can _always_ force a draw, >>because of the many checks it can give. And it often finds ways to pick >>up a pawn here and there. The exceptions occur when the rooks get doubled >>and can't be separated, but even then it is not a bad idea. >> >>I simply count a queen as equal to two rooks, period... And in 99.9% >>of the cases, that is at least correct... > >99.9%? 999 times out of 1000 the queen is stronger than two rooks?? I find >this very hard to believe, even in computer games. In general, deciding whether >the queen is stronger or the two rooks are stronger is impossible without >knowing more, in particular knowing about the pawns and if the rooks are >protected. If the pawns are loose and scattered and/or the rooks are loose, the >queen can do well, since the rooks can't defend them all and the queen can pick >them off. But give the rooks some protection and connected and defendable pawns >and the rooks can win much more often than the queen will. Perhaps what you are >seeing is an artifact of the kinds of pawn structures that arise in comp-comp >games, and not a feature of the relative value of queen versus rooks in >comp-comp games. > >By the way, the original position posted is so utterly drawn that seeing it as >+1.42 is pretty funny. > >Robin What I said, or what I _meant_ to say, is that in 99.9% of the games, the queen is _no worse_ than the two rooks. Which is why I consider having a queen equal to having two rooks roughly. Queen and pawn vs a pair of rooks will have the queen side better... I agree that in the posted game, a human says "all pawns on one side, this is a draw". But that is just one of many different possibilities. Considering the queen less than two rooks leads to even more mistakes. I try to keep the error term to a minimum, since zero is not possible. Note that this is simply my opinion, based on watching a _bunch_ of ICC games over the years. With my program playing both sides. As always, your results may well be different... and my opinion is certainly subject to change if I see something to change my mind...
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